1. Field of the Present Disclosure
The present disclosure relates generally to the field of video transmission, and may have particular application in the field of video security.
2. Description of the Related Art
Historically, the security and surveillance market has been dominated by analog closed-circuit television (CCTV) systems that have operated in a relatively isolated fashion and have been largely overlooked by any remarkable technological advancement. Expensive to install and vexing to maintain, CCTV systems require deployment of a complex network of coaxial cables or fiber cables and connecting to a number of analog cameras, stationary monitors, and videocassette recorders for archiving functions. Once the difficult installation procedure is completed, the buyer must also maintain a storage room to house the archives of videotapes. Reviewing historical video is time-consuming and tedious; as videotapes degrade rapidly, the quality of the archive will be poor. Since CCTV systems are analog-based (not digital), recorded images can only be viewed from videotapes using a video player connected to monitors. Once such a CCTV system is in place, even a minor change can be a major expense, with the hassle of running new cables and determining what hardware will work with the existing system.
The traditional approach to video surveillance and security employs coaxial, fiber-optic, or other types of cabling for connecting the various elements. There are numerous serious problems with this approach: Cables are easily damaged or severed by bad weather, birds, insects, accidents or saboteurs, and thus require nearly constant monitoring, maintenance and repair. If the cameras are somewhat distant from the monitoring station, then expensive trenching may be required to lay the cables. Furthermore, cables cannot be strung over long distances without sacrificing image quality or having to build expensive booster stations along the way. The use of cable thus requires the close physical proximity of the monitoring stations to the areas under video surveillance, or leasing expensive communications facilities from service providers.
The recent trend toward “convergence”—combining traditional CCTV applications with digital data networking technology—has ushered in a welcome change in the CCTV industry. The most widely available digital products are known generically as video servers. These devices can deliver live video automatically or on request, to a web browser or other professional security applications. This device typically connects up to 4 standard analog cameras via coaxial cable. The video server then digitizes, compresses, and distributes the video streams over an Ethernet interface onto a computer network, effectively turning analog cameras into network cameras.
Following on the heels of video servers has been the development of digital (also known as IP or Internet Protocol) cameras. These cameras are more expensive than their analog counterparts, but are able to connect directly to a digital computer network, and their video can be viewed from any workstation that is connected to the same network. The drawback to digital cameras is that they typically send large amounts of data (video streams contain very large amounts of data; on the order of 10 to 100 times more than is usually sent over a normal data network at one time) and can quickly overload a computer network. Even some of the newer cameras that can support video compression still send far more video data across the network than is usually seen in a data only network.
Once the video has been digitized, it can be easily recorded for later review using recently developed digital video recorder (DVR) technology rather than using old style videotapes. DVRs allow the recording of large amounts (thousands of hours) of video on very large computer hard disks, as well as provide fairly easy-to-use rewind, search and play functions on the video from any personal computer or web browser. However, most commercial DVR devices are standalone units and are not integrated with cameras or other network devices.
As security systems transition to digital technologies, there has been a strong desire to move toward wireless video surveillance using a variety of proprietary microwave technologies. Unfortunately, since most of the commercially available wireless products are designed for the computer data networking (as opposed to streaming video surveillance), network configuration is very complicated. Plus, video quality suffers from limited available wireless bandwidth (since video contains so much more data than normal data networks) and unstable wireless connections. Off-the-shelf wireless systems have very limited security capabilities and are subject to relatively easy interception. Expensive, specialized professional services for design, implementation, and ongoing support are also often required.
In addition to video surveillance, physical security also involves the need to monitor and manage a variety of other devices such as fire & burglar alarm control panels, access control mechanisms (swipe card, biometric or keypad entry for doors and gates), and environmental sensors (temperature, liquid, etc.). These devices are usually monitored and programmed using remote computer terminals that are connected to the devices using a serial data connection (known as RS-232, RS-422 or RS485 communications). Thus, long strings of wires must be run from these devices back to a central monitoring station where a terminal is used to monitor the activity at the devices and to program them to perform in the desired fashion.
In summary, the primary challenges facing implementers of security and surveillance systems today are several: 1) while wireless communication is an ideal choice to reduce the amount of cabling that has to be done both for surveillance cameras, the technology has many drawbacks (such as limited bandwidth and signal interference resulting in lost data) that especially disrupt the transmission of video; 2) many current wireless systems use proprietary radios and communication methods that prevent users from integrating them with the existing standards-based networks; 3) integrators wishing to provide remote monitoring and recording of surveillance video must today purchase several products from several vendors and tediously knit them together into an integrated solution using hardwired cables; and 4) security implementers wishing to provide remote monitoring and control of fire and burglar alarm panels, access control devices and environmental sensors along with surveillance video also have to select multiple products from multiple vendors and struggle with identifying the source of problems when the system fails to operate correctly.
Accordingly, what is needed are an integrated security controller and an enhanced video transmission method of the type disclosed herein.